Some types of wireless network technologies, such as Code Division Multiple Access (CDMA) technologies, allow a wireless communication device (WCD) to communicate via multiple wireless coverage areas simultaneously. For example, a radio access network (RAN) may transmit copies of the same bearer data to the WCD via traffic channels from each of several wireless coverage areas. This approach can increase the likelihood that the WCD will receive at least one copy of the bearer data. Additionally, the WCD may be able to combine two or more received copies of the bearer data such that the WCD can decode the received bearer data more reliably than if the WCD received only one copy of the bearer data. An analogous procedure may be used for bearer data transmitted by the WCD.
The wireless coverage areas with which a WCD is actively communicating may be referred to as the WCD's active set. As the WCD moves from place to place, or as the signal strengths that the WCD receives from members of its active set fluctuate, the RAN may add members to or remove members from the active set. The process of doing so may be referred to a “soft handoff.”
While soft handoff procedures are typically used mid-call, the RAN may also be able to assign traffic channels from multiple wireless coverage areas to a WCD at the beginning of a call. This technique, sometimes referred to as channel assignment into soft handoff (CASHO), may improve initial call quality, thereby increasing user satisfaction with the wireless service.